 You should try it every once in a while and you should be able to entertain yourself with your own thoughts. In fact, that's why I relish being on a plane when I have nothing to do, because it gives me that chance to do so much while I'm doing nothing. There's so much thinking I get to do and and hopefully nobody there to interrupt it. Now, if you look at somebody sitting in a chair thinking not doing anything. And you're shocked and confused.